Formation isolation valve

ABSTRACT

The present invention provides for high volume flow from a well. A retrievable formation isolation valve allows high volume flow through the remaining casing or tubing. Alternatively, a large bore valve configuration that is not retrieved, but remains as part of the casing, can be used. The present invention also includes methods to allow for high volume flow using retrievable isolation valves or large bore valves.

[0001] This application claims the benefit of U.S. ProvisionalApplication 60/356,496 filed Feb. 13, 2002.

BACKGROUND

[0002] 1. Field of Invention

[0003] The present invention pertains to isolation valves used insubsurface wells, and particularly to retrievable and large boreformation isolation valves.

[0004] 2. Related Art

[0005] It is often desirable to isolate a portion of a well. Forexample, a portion of the well may be isolated during insertion orretrieval of a drill string. It may also be desirable to isolate aportion of a well during perforation operations, particularly duringunderbalanced completion operations. There are several devices andmethods available to perforate a formation using underbalancedcompletion operations. Those include using special connectors such as“Completion Insertion and Retrieval under Pressure” connectors, placingformation isolation valves in the completion, and using wireline or coiltubing. However, each of those options has shortcomings, and none ofthose methods or devices allow, in the case of multiple productionzones, flowing each zone individually for clean up and testing.Therefore, there is a continuing need for improved isolation devices.

SUMMARY

[0006] The present invention provides for high volume flow from a well.A retrievable formation isolation valve allows high volume flow throughthe remaining casing or tubing. Alternatively, a large bore valveconfiguration that is not retrieved, but remains as part of the casing,can be used. The present invention also includes methods to allow forhigh volume flow using retrievable isolation valves or large borevalves.

[0007] Advantages and other features of the invention will becomeapparent from the following description, drawings, and claims.

BRIEF DESCRIPTION OF THE DRAWING

[0008]FIG. 1 is a schematic diagram of a completion assembly constructedin accordance with the present invention.

[0009]FIG. 2 is a schematic diagram of an alternative embodiment of acompletion assembly constructed in accordance with the presentinvention.

[0010]FIG. 3 is an enlarged view of a valve shown in the completionassembly of FIG. 2.

[0011]FIG. 4 is a schematic diagram of an alternative embodiment of acompletion assembly constructed in accordance with the presentinvention.

[0012]FIG. 5 is a schematic diagram of an alternative embodiment of acompletion assembly constructed in accordance with the presentinvention.

[0013]FIG. 6 is an enlarged view of a valve shown in the completionassembly of FIG. 5.

[0014]FIG. 7 is a schematic diagram of a flow controller used inaccordance with the present invention.

DETAILED DESCRIPTION

[0015] Referring to FIG. 1, a completion assembly 10 comprises aproduction tubing 12 having an interior passageway 14 in which adownstream formation isolation valve 16 and an upstream formationisolation valve 18 are disposed. Formation isolation valve 16 sealinglymounts to tubing 12 using downstream seal assembly 20, and formationisolation valve 18 sealingly mounts to tubing 12 using upstream sealassembly 22. When closed, each valve 16, 18 isolates that portion ofpassageway 14 that is downstream of that particular isolation valve fromthe upstream portion of passageway 14.

[0016] Production tubing 12 is shown disposed in a wellbore 24 havingmultiple production zones 26, 28. Production zone 26 is downstream ofproduction zone 28. In this description, flow is assumed to go fromproduction zones 26, 28 to the surface. Thus, upstream means in adirection opposite the flow and downstream means in the direction of theflow. Formation isolation valve 16 is mounted downstream of productionzone 26, and formation isolation valve 18 is mounted downstream ofproduction zone 28, but upstream of zone 26. Wellbore 24 may or may nothave a casing 30 mounted therein, or casing 30 may extend in only aportion of wellbore 24. The annular region 32 between tubing 12 andcasing 30, or wellbore 24 if casing 30 is not present, is sealed by apacker 34. Packer 34 isolates the downstream portion of annular region32, relative to packer 34, from the upstream portion.

[0017]FIG. 1 shows index couplings 36, 37 along predetermined sectionsof tubing 12. Index couplings 36, 37 are used to properly locate valves16, 18 relative to production zones 26, 28. Index couplings are wellknown and explained by Ohmer in U.S. Pat. No. 5,996,711.

[0018]FIG. 2 shows an alternative embodiment in which formationisolation valves 16, 18 are run in with casing 30 and cemented in placeto become integral with casing 30. That allows the use of a larger boreformation isolation valve than is possible when the isolation valve ismounted in the interior passageway 14 of tubing 12. In the embodiment ofFIG. 2, tubing 12 has a perforating gun 38 attached to the upstream endof tubing 12 and an actuator 40 attached to the upstream end of gun 38.In this case, actuator 40 is a shifting tool. The larger bore of valves16, 18 permit tubing 12, gun 38, and actuator 40 to pass through valves16, 18, when open.

[0019]FIG. 3 provides a more detailed view of formation isolation valve18. Formation isolation valve 18 is a ball valve. In the embodiment ofFIG. 2, valve 16 is also a ball valve. FIG. 3 also shows a valveoperator 42. Valve operator 42 is a mechanical link that responds to(shifting tool) actuator 40 to open or close the valve. Valve 16 has asimilar valve operator 42. Though shown as ball valves, formationisolation valves 16, 18 are not restricted to ball valves. Nor are theyrestricted to a particular type of valve operator, or even to a singletype of valve operator. For example, valve operator 42 can be ahydraulic, pneumatic, or electromechanical device. Actuator 40 for suchvalve operators may be pressure applied within the annulus or tubing, ahydraulic, pneumatic, electrical, or fiber optic control line, pressurepulse signals transmitted to a receiver, or a rupture disk.

[0020] Instead of being cemented in place as in FIG. 2, valves 16, 18can also be temporarily sealed in place inside casing 30. FIG. 4 showsvalve 16 suspended from a removeable packer 44. If removeable packer 44is used, valves 16, 18 are sized to allow tubing 12 to pass through openvalves 16, 18. Removeable packer 44 can be, for example, a retrievablepacker, as disclosed by Allen in U.S. Pat. No. 3,976,133, a cup packer,as disclosed by Hutchison in U.S. Pat. No. 4,385,664, or an inflatablepacker, as disclosed by Sanford, et al in U.S. Pat. No. 4,768,590.Removeable packer 44, by design, can be set in place to form a temporaryseal, and then released and retrieved at will. There are various designsand the present invention is not limited to the examples referred to inthis paragraph.

[0021] A similar arrangement can be placed inside tubing 12 instead ofcasing 30. This would produce an embodiment similar to that of FIG. 1,but removeable packers 44 would effectively replace index couplings 36,37 and seal assemblies 20, 22. Alternatively, seal bores (similar to apolished bore receptacle 56 shown in FIG. 1), in conjunction withselective profiles 50 (FIG. 6) or collets (not shown) may be used toposition and seal valves 16, 18 inside tubing 12. Therefore, one aspectof the present invention is a retrievable isolation valve that can beselectively opened and closed (e.g., a ball valve), and that can betemporarily set in a tubing or other well conduit.

[0022]FIG. 5 shows the use of formation isolation valves 16, 18 in amultilateral application. Valve 16 is placed in a main bore 46 ofwellbore 24 and valve 18 is placed in a lateral branch 48. In theembodiment shown, valve 16 is cemented in place with casing 30, asdescribed above. Valve 16 is a large bore valve allowing high volumeflow. Valve 18 is set in place using a selective profile 50 (see FIG. 6)to properly locate it within lateral branch 48. Valve 18 is set below aremoveable packer 44 to seal lateral branch 48 from main bore 46. Valve18 and packer 44 can be removed to permit high volume flow through thefull bore of branch 48.

[0023] To operate completion assembly 10 of FIG. 1 to performperforation operations, for example, an upstream portion 52 of tubing 12is run in wellbore 24 such that it extends from the bottom of casing 30past the most upstream production zone 28. In this embodiment, tubing 12is made of various sections joined as tubing 12 is lowered into wellbore24. Upstream portion 52 of tubing 12 is often referred to as a liner andcan be cemented in place in wellbore 24. A downstream portion 54 oftubing 12 is joined to upstream portion 52 using, for example, apolished bore receptacle 56. Packer 34 is shown just upstream ofpolished bore receptacle 56 in FIG. 1.

[0024] Index couplings 36, 37 are incorporated into tubing 12 such thatthey are properly positioned relative to production zones 26, 28 whenupstream portion 52 of tubing 12 is properly set into wellbore 24.Formation isolation valve 18, along with upstream seal assembly 22, isrun in and sealingly secured to upstream index coupling 37. Valve 18would normally be run into the well in the open position, but it couldbe run in closed and actuated open. Gun 38 and actuator 40 are run inthrough valve 18 and gun 38 is fired. After perforating is completed,gun 38 and actuator 40 are extracted, with actuator 40 closing valve 18as it passes valve operator 42. That isolates perforated zone 28. Valve18 can be opened to allow zone 28 to flow to remove debris, and thenclosed again to isolate zone 28.

[0025] Formation isolation valve 16, along with downstream seal assembly20, is then run in and sealingly secured to downstream index coupling36. Gun 38 and actuator 40 are run in through valve 16 and gun 38 isfired. After perforating is completed, gun 38 and actuator 40 areextracted, with actuator 40 closing valve 16 as it passes valve operator42. That isolates perforated zone 26. Valve 16 can be opened to allowzone 26 to flow to remove debris, and then closed again to isolate zone26. Then, valves 16, 18 are pulled out of the well, as described below,to present the unrestricted, large inner diameter of tubing 12 for highrate flow.

[0026] Valves 16, 18 can be removed in various ways. The releaseelements described in this paragraph are known in the art and not shownin the figures of this specification. In the embodiment of FIG. 1, indexcoupling 36, for example, can have a sliding sleeve to shear connectingpins securing seal assembly 20 to coupling 36, and a “fishing” tool canretrieve the released components. Similarly, the blended embodiment ofFIGS. 1 and 4, in which removeable packer 44 effectively replaces sealassemblies 20, 22 and index couplings 36, 37, can be retrieved becauseof the design of the packer itself. Valves 16, 18 could also be setusing keys, for example, so that valves 16, 18 could be milled.

[0027] Operation of the embodiment of FIG. 4 is similar to that ofFIG. 1. A first removable packer 44, with formation isolation valve 18,is set downstream of zone 28. Gun 38 and actuator 40 are run in ontubing 12 through valve 18 and gun 38 is fired. After perforating iscompleted, gun 38 and actuator 40 are extracted, and actuator 40 closesvalve 18 to isolate perforated zone 28. Valve 18 can be opened to allowzone 28 to flow, and then closed again to isolate zone 28. A secondremovable packer 44, with formation isolation valve 16, is setdownstream of zone 26. Gun 38 and actuator 40 are run in on tubing 12through valve 16 and gun 38 is fired. After perforating is completed,gun 38 and actuator 40 are extracted, with actuator 40 closing valve 16to isolate perforated zone 26. Valve 16 can be opened to allow zone 26to flow, and then closed again to isolate zone 26. Then, valves 16, 18are pulled out of the well, as described above, to present theunrestricted, large inner diameter of casing 30 or tubing 12, set with apacker 34, for high rate flow.

[0028] In other embodiments, such as that of FIG. 2, valves 16, 18 neednot be removed. Because valves 16, 18 are set in casing 30, they aresized to accommodate the full bore of tubing 12.

[0029] Operation of the embodiment of FIG. 2 is essentially the same asfor the embodiment of FIG. 1, except valves 16, 18 are set in casing 30instead of tubing 12. Casing 30 is assembled with valves 16, 18 placedso that they are properly positioned relative to zones 26, 28 whencasing 30 is set and cemented in place. Gun 38 and actuator 40 are runin through valve 18 and gun 38 is fired. After perforating is completed,gun 38 and actuator 40 are extracted, with actuator 40 closing valve 18as it passes valve operator 42. That isolates perforated zone 28. Valve18 can be opened to allow zone 28 to flow, and then closed again toisolate zone 28.

[0030] Gun 38 and actuator 40 are then run in through valve 16 and gun38 is fired. After perforating is completed, gun 38 and actuator 40 areextracted, with actuator 40 closing valve 16 as it passes valve operator42. That isolates perforated zone 26. Valve 16 can be opened to allowzone 26 to flow, and then closed again to isolate zone 26. Valves 16, 18can then be actuated open to allow production through casing 30, ortubing 12 can be run in, with a packer 34 set downstream of valve 16 toseal annular region 32. Tubing 12 would allow well fluid to be producedthrough passageway 14.

[0031] The embodiment of FIG. 5 would be operated similarly. Each zone26, 28 could be perforated and “flowed” in isolation from the otherzone. Those valves that are removeable can be removed to provide forhigh rate flow. Those valves that remain in place are sized toaccommodate high volume flow.

[0032] The present invention overcomes the shortcomings mentioned in theBackground section of this specification, as well as others notspecifically highlighted. In particular, perforating long sections withspecialized connectors or coil tubing takes a long time, and usingformation isolation valves in a conventional manner does not provide alarge inner diameter for a high production rate. The present inventionincludes various apparatus and methods to achieve high volume flow ratessubsequent to performing desired completion operations. The presentinvention also allows placement of other devices, such as a flowcontroller 58 (FIG. 7), either after performing initial operations orduring a later intervention.

[0033] Although only a few example embodiments of the present inventionare described in detail above, those skilled in the art will readilyappreciate that many modifications are possible in the exampleembodiments without materially departing from the novel teachings andadvantages of this invention. Accordingly, all such modifications areintended to be included within the scope of this invention as defined inthe following claims. It is the express intention of the applicant notto invoke 35 U.S.C. § 112, paragraph 6 for any limitations of any of theclaims herein, except for those in which the claim expressly uses thewords ‘means for’ together with an associated function.

What is claimed is:
 1. A completion assembly for use in a wellcomprising: a conduit having an interior passageway; and a first valvesealingly and removeably mounted to the conduit in the interiorpassageway, the first valve being capable of opening and closingmultiple times.
 2. The completion assembly of claim 1 in which the firstvalve is a ball valve.
 3. The completion assembly of claim 1 furthercomprising an actuator.
 4. The completion assembly of claim 3 in whichthe actuator is a shifting tool.
 5. The completion assembly of claim 3in which the actuator is a pressure pulse signal.
 6. The completionassembly of claim 3 in which the actuator is an applied pressure.
 7. Thecompletion assembly of claim 3 in which the actuator is a hydraulic,pneumatic, electrical, or fiber optic control line.
 8. The completionassembly of claim 3 in which the first valve has a first valve operatorto open and close the first valve in response to the actuator.
 9. Thecompletion assembly of claim 1 in which the first valve is placeddownstream of a first formation.
 10. The completion assembly of claim 1further comprising a second valve sealingly and removeably mounted inthe interior passageway, the second valve being capable of opening andclosing multiple times.
 11. The completion assembly of claim 10 in whichthe first valve is placed downstream of a first formation and the secondvalve is placed downstream of a second formation and upstream of thefirst formation.
 12. The completion assembly of claim 10 in which thesecond valve is a ball valve.
 13. The completion assembly of claim 10further comprising an actuator to selectively open and close the firstand second valves.
 14. The completion assembly of claim 13 in which theactuator is a shifting tool.
 15. The completion assembly of claim 13 inwhich the actuator is a pressure pulse signal.
 16. The completionassembly of claim 13 in which the actuator is an applied pressure. 17.The completion assembly of claim 13 in which the actuator is ahydraulic, pneumatic, electrical, or fiber optic control line.
 18. Thecompletion assembly of claim 13 in which the first valve has a firstvalve operator to open and close the first valve in response to theactuator and the second valve has a second valve operator to open andclose the second valve in response to the actuator.
 19. The completionassembly of claim 1 in which the first valve is placed in a branch of amultilateral well.
 20. An isolation system for use in a well comprising:a casing having an interior passageway; and a first valve mounted to thecasing and registering with the interior passageway when the first valveis open, the first valve being capable of opening and closing multipletimes.
 21. The isolation system of claim 20 further comprising anactuator to open and close the first valve.
 22. The isolation system ofclaim 20 in which the first valve is a ball valve.
 23. The isolationsystem of claim 20 further comprising a second valve mounted to thecasing and in registry with the interior passageway when the secondvalve is open, the second valve being capable of opening and closingmultiple times.
 24. The isolation system of claim 23 further comprisinga tubing, the tubing being able to pass through the open first andsecond valves.
 25. The isolation system of claim 23 further comprisingan actuator to selectively open and close the first and second valves.26. The isolation system of claim 25 in which the actuator is a shiftingtool.
 27. The isolation system of claim 25 in which the actuator is anapplied pressure.
 28. The isolation system of claim 25 in which theactuator is a hydraulic, pneumatic, electrical, or fiber optic controlline.
 29. The isolation system of claim 25 in which the first valve hasa first valve operator, and the second valve has a second valveoperator, each valve operator independently opening or closing itsrespective valve in response to the actuator.
 30. The isolation systemof claim 20 in which the first valve is removeable.
 31. The isolationsystem of claim 20 in which the first valve is part of the casing andthe casing is cemented in the well.
 32. A completion assembly deployedwithin a multilateral well having a main bore and a lateral bore, thecompletion assembly comprising: a first valve sealingly mounted in themain bore; and a second valve sealingly mounted in the lateral bore; andin which at least one of the valves is removeable, and at least one ofthe valves can be opened and closed multiple times.
 33. The completionassembly of claim 32 further comprising a tubing, the tubing being ableto pass through at least one of the open valves.
 34. The completionassembly of claim 32 further comprising an actuator to selectively openand close the first and second valves, the first and second valves beingcapable of opening and closing multiple times.
 35. The completionassembly of claim 34 in which the actuator is a shifting tool.
 36. Thecompletion assembly of claim 34 in which the actuator is an appliedpressure.
 37. The completion assembly of claim 34 in which the actuatoris a hydraulic, pneumatic, electrical, or fiber optic control line. 38.The completion assembly of claim 34 in which the first valve has a firstvalve operator, and the second valve has a second valve operator, eachvalve operator independently opening or closing its respective valve inresponse to the actuator.
 39. A retrievable valve for use in a wellcomprising: a housing having a central bore; an interior seal moveablymounted in the housing, the interior seal being moveable multiple timesbetween an open position to allow flow through the central bore and aclosed position to prevent flow through the central bore; and a releaseconnected to the housing.
 40. The valve of claim 39 further comprisingan outer seal to seal between the housing and an outer constraint. 41.The valve of claim 39 in which the interior seal resides on a ballhaving a central passage that registers with the central bore when thevalve is open.
 42. The valve of claim 39 in which the release is aremoveable packer.
 43. The valve of claim 39 in which the release is aselective profile.
 44. An apparatus for use in a well comprising: afirst valve sealingly and removeably mounted in an interior passagewayof a casing and registering with the interior passageway when the firstvalve is open, the first valve being capable of opening and closingmultiple times.
 45. The apparatus of claim 44 further comprising asecond valve sealingly and removeably mounted in the interior passagewayof the casing and registering with the interior passageway when thesecond valve is open, the second valve being capable of opening andclosing multiple times.
 46. A method for isolating a portion of a wellcomprising: attaching a first removable valve to a conduit in the well;actuating the first valve open or closed; performing operations in thewell; and removing the first valve from the conduit.
 47. The method ofclaim 46 in which performing operations comprises perforating aformation upstream of the first valve.
 48. The method of claim 46further comprising allowing formation fluid to flow to remove debrisfrom the well.
 49. The method of claim 46 further comprising maintaininga well pressure at or below a formation pressure.
 50. The method ofclaim 46 further comprising: attaching a second removable valve to theconduit downstream of the first valve; actuating the second valve openor closed; performing operations in the well; and removing the secondvalve from the conduit.
 51. The method of claim 50 in which performingoperations comprises perforating a formation upstream of the secondvalve.
 52. The method of claim 46 further comprising: running aperforating assembly through the open first valve; perforating a firstproduction zone while pressure in the well is underbalanced; extractingthe perforating assembly; attaching a second removable valve to theconduit downstream of a second production zone, the second productionzone being downstream of the first valve; running the perforatingassembly through the open second valve; perforating the secondproduction zone while pressure in the well is underbalanced and thefirst valve is closed; extracting the perforating assembly; andextracting the first and second valves from the conduit.
 53. The methodof claim 46 in which the first valve is attached to an index coupling.54. The method of claim 53 further comprising attaching a flowcontroller in the index coupling after removing the first valve.
 55. Amethod for isolating a portion of a well comprising: inserting a casinghaving at least a first isolation valve in the well; actuating the firstvalve open or closed; performing operations in the well; and producingfluid from the well.
 56. The method of claim 55 further comprisingactuating a second valve open or closed.